Former Lebanese Prime Minister Rafik Hariri was killed today in a huge bomb blast. Nine others were killed, and over a hundred were wounded.

Hariri, a Sunni Muslim, was perhaps the single biggest businessman in Lebanon, with most of his money coming from Saudi Arabia (he worked closely with the royal family and acquired Saudi citizenship.) He was also, to a certain extent, a reformist and an opponent of the re-election of President Emile Lahoud, who managed to force him out by securing Syrian support for another mandate (one that they had to amend the constitution to make possible.)

This is obviously a huge deal and the sign of a worrying trend in Lebanon. Over the past few months I'd noticed that the old warlords, notably General Michel Aoun, several members of the Gemayel clan and Druze leader Walid Jumblatt, were making more and more statements. People from Lebanon were telling me, in worried tones, that the situation was starting to look like the tensions in 1975 just before the civil war started (it ended in 1992, and Lebanon has only begun to recover and is still burdened with enormous foreign debt.)

I note that the Daily Star, Lebanon's leading English-language publication, has no more than an AFP story so far. (They were down a few minutes ago.) They may have more later on, although they are generally politically cautious on Lebanon. The big question is going to be whodunnit, and what consequences will there be for internal stability and inter-confessional relations. If this is a move by Maronites to prevent Hariri from securing help from outside Lebanon to regain the prime ministership, things could become very ugly. And in any case, it will deliver a blow to the country economically, as Hariri's businesses account for a lot of activity.

Issandr El Amrani is a Cairo-based writer and consultant. His reporting and commentary on the Middle East and North Africa has appeared in The Economist, London Review of Books, Financial Times, The National, The Guardian, Time and other publications. He also publishes one of the longest-running blog in the region, www.arabist.net.